I bought this “toy” from Amazon used. I figured it wouldn’t work based on reviews but figured it wouldn’t be too complicated to repair. Once opened this transistor was fried. I don’t have any knowledge about transistors. What should I replace it with, the same or different transistor. The PCB looks horrible, I can clean it up. The reviews say they usually work for short period of time and I’m guessing it then blows the transistor. Is it worth fixing or send it back? It’s 60W DC 12V
To find out what apart is the first stop is to enter the info from the part into Google and see what comes up.
NEC 0772 transistor NEC 0772 transistor - Google Search
The pictures in the search match, so it’s a 2SB772.
Put 2SB772 in the Digi-Key search box and you’ll find the part or a substitute.
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Aye PaulHutch is correct.
I’d feel comfortable using an alternative part like KSB772YS onsemi | Discrete Semiconductor Products | DigiKey for that.
From what I’ve read these are in pairs. I did not realize that the two pair have different numbers. Any reason these would fry so quickly?
Would this be correct for the second pair?
Thank you for your help!
I would use this link: https://www.digikey.com/short/r084w57w . The one you provided is Marketplace with no stock or lead time. This one will get you some stock. I am not sure why they would go bad. There could be multiple reasons. Honestly I am not sure if NEC still makes them so they could just be older. Could have had a power surge.
PaulHutch, Kristof_2649 and Verna_1353
Thank you so much for your help!!!
I ordered two of each that were recommended in case I would need to replace all four on the board. I first replaced the burnt PNP transistor. Tested great for the sirens but voice over PA was not loud. Replaced the second PNP transistor same results. I replaced both of the NPN transistors, tested again PA was loud. Awesome! Since the item was used on Amazon figured it wouldn’t work because they don’t test returned items and I thought it can not be that difficult to fix. Sure enough it’s fixed for about $10. I told Amazon it didn’t work but wanted to try and fix it but no guarantee that it would work. They let me keep it and gave me a credit. Thank you Digi-Key Electronics!!
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